The study and practice of dermatology care using interactive audio, visual, and data communications from a distance is called teledermatology. A teledermatology practice (TP) provides teleconsultation as well tele-education. Initially, dermatologists used videoconference. Convenience, cost-effectiveness and easy application of the practice made "store and forward" to emerge as a basic teledermatology tool. The advent of newer technologies like third generation (3G) and fourth generation (4G) mobile teledermatology (MT) and dermatologists' interest to adopt tertiary TP to pool expert (second) opinion to address difficult-to-manage cases (DMCs) has resulted in a rapid change in TP. Online discussion groups (ODGs), author-based second opinion teledermatology (AST), or a combination of both are the types of tertiary TP. This article analyzes the feasibility studies and provides latest insight into TP with a revised classification to plan and allocate budget and apply appropriate technology. Using the acronym CAP-HAT, which represents five important factors like case, approach, purpose, health care professionals, and technology, one can frame a TP. Store-and-forward teledermatology (SAFT) is used to address routine cases (spotters). Chronic cases need frequent follow-up care. Leg ulcer and localized vitiligo need MT while psoriasis and leprosy require SAFT. Pigmented skin lesions require MT for triage and combination of teledermoscopy, telepathology, and teledermatology for diagnosis. A self-practising dermatologist and national health care system dermatologist use SAFT for routine cases and a combination of ASTwith an ODG to address a DMC. A TP alone or in combination with face-to-face consultation delivers quality care.

The study and practice of dermatology using interactive audio, visual, and data communications from a distance is teledermatology. [1] A teledermatology tool refers to the technology or modality used to deliver dermatology care. The application of teledermatology tool (technology) to deliver dermatology care is called teledermatology practice [2] (TP). The aim of TP is to reach the unreached for dermatology care in remote geographic regions. It involves good general practitioner (GP) and dermatologist interaction. In recent times, with the advent of tertiary TP for difficult-to-manage cases (DMC), the scope of TP has widened. There is a specialist-to-specialist interaction for second opinion and continuing medical education that updates a dermatologist.

History of Teledermatology

In 1906, Wilhelm Einthoven discovered telecardiogram [3] and was successful in the transmission of electrocardiogram using a telephone network. The Nebraska Project, [4] USA, in 1959, used videoconference (VC) for psychiatry patients which was conducted between two hospitals within a distance of 150 kilometers. Between 1960 and 1970, research to monitor astronauts' heart rate, blood pressure and electrocardiogram was conducted. [5] The term teledermatology was introduced by Prednia and Brown. [1] Teledermatology in a nursing home setting was first demonstrated by Zelickson and Homan. [6]

The advent of Medline and online reprint request, teledermoscopy, mobile teledermoscopy, telepathology, revolution and advancement in 3G and 4G mobile teledermatology (MT), and tertiary teledermatology like online discussion group (ODG) and author-based second opinion teledermatology (AST) has revolutionized TP.

TP is performed everywhere including as far as South Pole, [7] as remote as Faroe Islands, [8] rural India, [9] USA, [10] Africa, [11] in austere environments, [12] and nursing home settings. [13] A double-blind randomized control trial provides evidence for a therapeutic response of a drug. Similarly, the feasibility studies provide evidence regarding the application of teledermatology tools and play a key role to determine the TP.

TP reduces frequent visits, travel, and waiting period and minimizes the treatment cost. [14] It is important in elderly who suffer from chronic conditions like psoriasis and leg ulcer that call for frequent follow-up care. TP can be used in national health programs [2] to screen for leprosy and melanoma. TP helps in counseling and in initial examination prior to dermatosurgery. [15] TP facilitates to pool expert opinions and helps in continuing medical education. [16]

Poor net connectivity, poor image quality, and lack of referral proforma data can limit TP. [17] Legal issues, absence of in-person examination, varied treatment protocols between countries, doubts regarding the technology to offer second opinion can interfere with tertiary TP. [18] Time constraints, unavailability of the patient and doctor at the same time or the longer time taken to opine on still images, and patient discomfort in front of the camera, especially so for private part lesions, may limit TP. [14]

Importance and Need of the Teledermatology Practice Classification

A systematic classification is required to conduct study and research, and plan and allocate budget. [2] TP tools are broadly categorized [14],[16] as data sent as 1) motion images, VC; (2) static images, store-and-forward teledematology (SAFT); (3) and a combination of both static and motion images, hybrid teledermatology (HT). The above tools are called stationary TP tools. [16] Later in 2004, Braun [19] from Sweden introduced MT for the management of leg ulcer. In 2008, the classification of TP was proposed. [2] It is based on technology, health care professionals involved in teleconsultation, and special area of teledermatology application like teledermoscopy and telepathology. [2] Recent advances in tertiary teledermatology and 3G/4G MT which were not in the earlier classification [2] are now incorporated in the proposed revised classification [Figure 1]. TP tools are broadly divided into (a) basic TP to address the regular dermatology cases and (b) tertiary TP for DMCs to seek second opinion. Special areas of application include teledermoscopy, mobile teledermoscopy, telepathology, or their combination, placed in tertiary teledermatology, as it requires special expertise in the field to diagnose or offer second opinion.

Static images of clinical and histopathological data are accessed anytime and anywhere. They are transferred from a GP to a specialist to deliver the management. A diagnosis agreement of 68%, [20] 89%, [21] 58%, [22] and 48% [17] has been documented. Recently, various feasibility studies have confirmed a good diagnostic accuracy when SAFT is compared to face-to-face consultation, [23] skin neoplasms, [24] and pediatric dermatology. [25] Dermatology cases that can be diagnosed by face-to-face examinations (spotters) have a good diagnostic accuracy by SAFT. Good quality images are taken by the GP in a short time. [26] The comparison between the clinical dermatologist and teledermatologist reveals that there is a small difference in the interobserver accuracy of SAFT for diagnostic accuracy, histopathological analysis (gold standard), and management plan for skin neoplasms. [24] A diagnostic agreement and management plan is good and teledermatology benefits remote geographic regions. [27] SAFT has a good diagnostic concordance for fever with rash in children. [28] SAFT is cheap, and easy to set up and practice. It is the commonest teledermatology tool as most of the cases are dealt and often regarded as a basic model for a TP. [2]

Videoconference

It is a live or interactive teledermatology. GP, patient and specialist interact with one another. Various feasibility studies [29],[30] have confirmed good diagnostic accuracy when VC is compared to face-to-face consultation. VC needs appropriate equipment and it is very expensive. Motion images are transmitted using satellite communication [5],[31],[32] (SATCOM) from a referral hospital to a remote region. A bus or a van mounted with a satellite communication travels to the camp destination region and establishes the connectivity with a tertiary center to conduct skin camps in rural India. Indian space research organization provides infrastructure. [31]

Hybrid teledermatology

This is a combination of both VC and SAFT to overcome the shortcomings faced when either of them is used individually. [33] Intercomparison of VC, SAFT, and HT [2],[24],[27],[29],[34],[35] reveals a face-to-face interaction in VC and HT, that is absent in SAFT. Good patient and physician satisfaction along with good diagnostic accuracy is achieved in all. The simultaneous presence of a health care professional is required in VC and HT and his or her presence may not be required in SAFT. SAFT is the most cost-effective and convenient TP tool compared to VC. The time taken for consultation is least for SAFT and more in VC and HT. Motion images are used in VC, still images are used in SAFT, and both the types of images are used in HT. Intraobserver reliability is very high in teledermatology. A hybrid system with audio is no better than SAFT alone. [35] The comparison of in-person examination, with VC and SAFT, revealed a comparable diagnostic and management agreement plan. Higher dermatologist confidence with in-person examination compared to either SAFT or VC is observed. Dermatologist confidence in SAFT and VC did not differ statistically from each other. [34] A randomized prospective outcome study demonstrated SAFT results in an equivalent clinical outcome compared with a conventional clinic-based consultation. [35]

Mobile teledermatology

The term cellular teledermatology is avoided and MT should be used instead as this term represents the transmission of images via mobile phones [19],[36] as well as through personal digital assistants. [37] Motion and still images are transferred using cellular phones. Images of leg ulcers are transferred from a digital camera to a computer system or a cellular phone. [19] Patients with a leg ulcer, nurses, or health care workers send periodic images from a remote area to a dermatologist. Treatment is offered and follow-up is performed periodically. Cost, travel, and time are saved. Various feasibility studies [38],[39] have confirmed a good diagnostic accuracy when MT is compared with face-to-face consultation.

Teledermatopathology

Transmission of histopathological images of skin using information technology for expert opinion is called teledermatopathology. [40],[41],[42],[43],[44],[45] Teledermatopathology is achieved by (i) video-image (dynamic) analysis; (ii) store and forward (static); and (iii) web-based virtual slide system. [46] A virtual slide system is a recently developed technology where a robotic microscope is used; any field of the specimen is selected for better digitalization at any required magnification at the discretion of the dermatopathologist. [43]

Teledermoscopy

Pigmented skin lesions and melanoma are analyzed based on the dermoscopic criteria [47],[48] that depend on characteristic changes in epidermis and dermis. Dermoscopy images [49],[50],[51],[52],[53] are transmitted for expert opinion using routine TP tools like SAFT or tertiary TP for second opinion. If these images are transferred using mobile technology, it is called mobile teledermoscopy. Pigmentary skin lesions are screened by MT. [54]

Tertiary TP

DMCs need second opinion using information technology from one or more experts to provide dermatology care. It is referred as second opinion or tertiary TP. Expert opinion, resident training, and continuing medical education are the objectives of tertiary TP. [55] Previous reviews [2],[55] suggest SAFT and HT for second opinion TP. Currently, there are three types of tertiary TP: (a) ODG, [56],[57],[58],[59],[60],[61],[62] (b) AST, [18] (c) and the combination of ODG and AST [63][Figure 1].

Online discussion groups

DMCs are a challenge to the health care system. An ODG is formed with a group of dermatologists who share constructive suggestions [56],57],[58] for a submitted case. Feasibility studies have confirmed 81% concordance with face-to-face consultation. [58] Members of academic societies like Indian Association of Dermatologists, Venereologists and Leprologists have formed an ODG at ACAD_IADVL@yahoogroups.com (an e-mail group) and participate in regular academic discussions. Telederm.org, [56] Rxderm, [57] Virtual Grand Rounds in Dermatology, [59] and Black Skin Dermatology Online [60] are the examples of ODGs. Experts may be unavailable for an instant case, or dermatologists and allied research workers who might have carried out research involving a DMC may not have registered at the site and at times consensus may not be reached for a case without these experts. These limitations of ODG are overcome by AST. [18] Online blogs are another form of ODGs.

Author-based second opinion teledermatology

Experts who have previously worked and published may offer valuable suggestions for a DMC. A dermatologist performs a PubMed survey, notes author's e-mail, obtains the literature, reads, analyzes, and obtains constructive suggestions for both the case and related literature from the author. This process updates the physician and delivers quality health care.

Steps involved in AST are summarized in [Figure 2]. A recent online author survey [18] observed that the author who has previously worked and published on the instant case offers constructive suggestions; quality of opinion is excellent as opinions are pooled from experts who have done original work. Evidence-based medical practice is followed. [18]

Figure 2: The steps involved in author-based second opinion teledermatology

The limitations of ODGs are overcome by enrolling the experts. In special situations, the moderator apart from offering suggestions invites second opinion from the author who has published the relevant work on an instant case and the moderator can pool and summarize collective opinions and offer constructive suggestions based on the literature. Evidence-based medicine is thereby practised. Time taken in an ODG to answer the requests were rapid: 80 (60%) of the requests of the ODG group were answered within 1 day. [61] The exact time needed for AST has not been reported yet; however, reprint requests sent to dermatology authors have been responded (63%) to positively and rapidly in <2 days. [64]

Implementation of TP (applied teledermatology)

There are five important factors that determine the appropriate teledermatology tools to be used in TP. The acronym "CAP-HAT" represents these factors - case, approach, purpose, health care professionals, and teledermatology tool [63] (technology). The letters used in the acronym and the five important factors that determine TP are shown in [Figure 3]. It is important to assess the utility before an acronym is introduced. [65] The application and utility of the acronym CAP-HAT in TP is summarized in [Figure 4]. The sequence of letters "A" and "P" in the acronym "CAP-HAT' is interchanged for convenience.

Figure 3: The acronym "CAP-HAT" represents as cardinal factors to design a teledermatology practice. The two words in the acronym "CAP" and "HAT" are related as thesaurus and therefore the acronym is represented as "CAP-HAT." and it is easy to remember and reproduce. The repeated letter "A" in the acronym does not refer to any factor; it is a conjunction ("and"). that links the fifth factor "technology"

Nurse or health care workers can send in periodic images using MT. [74] GP can send images to the dermatologist and use SAFT [74] [[Figure 4]b]. A nurse or a patient send images, and psoriasis severity can be evaluated using MT. [32],[72] Patient empowerments in teledermatology to deliver follow-up care in chronic dermatology cases like psoriasis, [72] acne, [73] and leg ulcer [71] are documented. A compliance management system using MT for the periodic assessment of psoriasis is proposed. [75] MT text messages are innovative, low cost, and a reminder tool to improve adherence to treatment. [76] A National Health Care System (NHS) should implement text messages addressing adherence to treatment, education, and awareness especially for diseases like leprosy covered by national health programs. This process provides education and builds confidence in patients. Medical treatment and/or dermatosurgical counseling or follow-up care for vitiligo is delivered. [15]

Diagnosis and management of melanoma and pigmented skin lesions are challenging and require initial face-to-face examination followed by TP with more than one teledermatology tool. [58],[77] SAFT with ODGs and AST or in combination with telepathology, teledermoscopy, and or mobile teledermoscopy is of additive value with an improved diagnostic accuracy [78],[79] compared to face-to-face examination and facilitates second opinion [63] [[Figure 4]c].

Nurses or trained health care workers triage pigmented skin lesions [77],[78],[79],[80],[81],[82],[83],[84],[85],[86],[87] or survey or mass screen the cases using MT and can send in images directly to the tertiary center for histopathological examination or route the images through a GP [[Figure 4]d]. Infectious cases are diagnosed by SAFT. [88] Screening for occupational eczema is performed using SAFT. [89] The evaluation of the scoring system for hand eczema is feasible for SAFT. [90] To screen or triage melanoma, pigmented skin lesions, leprosy, and endemic cases like leishmaniasis, one can adapt initial TP followed by face-to-face examination. In routine practice, nurses use MT and GPs use SAFT to triage cases and provide further management in a tertiary center [[Figure 4]e]. The interpretation of patch testing is performed by SAFT [91] [[Figure 4]g]. A dermatologist uses VC or HT for dermatology cases like HIV/AIDS and genodermatoses [[Figure 4]f] that require counseling and health education. [92],[93],[94],[95]

The implementation of TP

The application of TP tools is reviewed here. [2],[96],[97],[98] An ideal TP should address routine cases as well as DMCs. A combination of (a) basic or routine and (b) tertiary TP are required to deliver complete TP. [63] Self-practicing dermatologists [99],[100],[101],[102] and NHS dermatologists [63],[103],[104],[105] use SAFT for routine practice. They use ODGs and AST to address DMCs [63] [[Figure 4]h]. Self-practicing dermatologists organize TP with a group of known GPs from the region. They join the ODG formed by the national academic body, like Indian Association of Dermatologists, Venereologists, and Leprologists (IADVL ACAD), for DMC and offer treatment [Figure 5].

Figure 5: The organization of teledermatology practice for a self-practicing dermatologist: It comprises a basic model SAFT, where a GP interacts with a dermatologist for regular cases (spotters) along with ODG and AST to obtain a second opinion on difficult-to-manage cases (modified with permission from Kanthraj GR. J Eur Acad Dermatol Venereol. 2010; 24:961-6. Authors' willingness for sencond opinion teledermatology in difficult to manage cases: 'An online survey'

The Netherlands NHS [104] has successfully implemented SAFT for TP. Over 185 dermatologists and 2500 GPs performed 33,000 teledermatology consultations with reimbursement by the Dutch healthcare insurance system in a period of 4 years. [104] Recently, a TP model for a NHS is proposed. [63] In the Indian context, this model [63] can be applied in respective state and central government health services. Governments' health service dermatologists form an ODG and among them two or more senior dermatologists are appointed as moderators by the health service. The NHS provides the information technology infrastructure. The moderator identifies DMCs, and offers and pools opinions either from experts within the ODG or AST. A dermatologist can submit or offer opinions for other submissions. This process enables a dermatologist to update recent advances, and earn CME credit and reimbursement. DMCs are not neglected in the community as debated earlier. Epidemiology data are maintained. House surgeons are trained for history taking, photography, and sending images for teleconsultation in rural areas. [105]

Cost-effective studies [106],[107],[108],[109],[110],[111] on implementation of TP have found it to be economical. A study on the economic evaluation of teledermatology reveals that SAFT is 1.6-fold cheaper when compared with the conventional letter referral system to triage skin cancer patients. [107] TP, if implemented appropriately [63] can deliver the quality care without any burden on the financial position of a NHS. A recent study from Netherlands [111] confirmed that TP is cost effective if the distance to a dermatologist is larger (≥75 km) or when more consultations (≥37%) are prevented by TP.

Face to face consultation versus TP

There is a debate to compare both face-to-face examination and TP. [112] Patients still prefer a face-to-face consultation, with one study reporting that 40% felt "something was missing" when the dermatologist was not seen in person. [112] A face-to-face examination binds the physician and patient and TP is not a substitute. Legal principles of face-to-face consultation will apply to TP. [14] Pooling expert opinions across the globe is a great advantage of a TP, that is difficult to achieve in a face-to-face consultation. Therefore, a combination of both face-to-face consultation and TP in appropriate situations as illustrated in [Figure 6] can deliver quality care. This approach minimizes the shortcomings of either face-to-face examination or TP alone.

Figure 6: Application of teledermatology practice and face-to-face consultation in appropriate clinical situation to deliver quality care: A dermatologists approach toward a case with a combination of both face-to-face and teledermatology practice or individually depending on appropriate clinical situations to deliver quality care and minimize the short comings of either face-to-face examination or teledermatology practice alone

Privacy legislation in Australia has made access to the blogs possible, only by invitation. [85] No specific regulation exists till date for ODG, blogs, and AST where experts across the globe interact. Uniform international guidelines are required. In general, the practice principles of face-to-face examination apply for a TP. [14] The confidentiality and protection of images are important. [14]

Future Perspective in Teledermatology

The advent of the 3G/4G mobile teledermatology revolution has advanced to a point where they are as good as small computers. MT is basically changing into another method of SAFT and even VC with video-enabled smart phones [Figure 1]. There are no feasibility studies yet; future studies in this area should expand this information. The widespread introduction of 3G /4G services in India and elsewhere will in all probability spark an increased use of advanced MT-based consultations.

Conclusion

An ideal TP should have a teledermatology tool that addresses regular cases as well as DMCs. A self-practicing dermatologist and a NHS dermatologist use SAFT for regular cases and adopt ODG, AST, or both for DMCs guided by moderators. Active survey (house-to-house) screening, pigmented skin lesions (melanoma), and leprosy require MT. Five factors determine the design of a TP. Feasibility studies have demonstrated the role of TP in various situations. TP alone or in combination with face-to-face consultation delivers quality care. Medical graduates, interns, and dermatology residents need encouragement to participate in TP as it updates their knowledge and it should be included in the teaching curriculum.